Calculation of High Temperature Crude-Oil/Water/Vapor Separations Using Simulated Distillation Data

Abstract

Summary High-temperature crude-oil/water/vapor separation takes place in steamflooding and in-situ combustion processes. It also takes place in hydrocarbon recovery from deep volatile oil and condensate reservoirs. A practical procedure that uses the Holland and Welch method and sirilulated distillation data was developed to calculate crude-oil/water/vapor separations at 387 and 456°F [197 and 236°C]. The overhead yields obtained from the calculations were expressed as a function of the steam distillation factor. The Vw/Voi results were compared with laboratory crude-oil steam distillation data. The approach satisfactorily predicted the overhead yields of 13 out of 16 crude oils with an average error of 12% (±3.6% in yield). This is within experimental error of crude-oil steam distillation. Twelve pseudocomponents of crude oils were selected and characterized with simulated distillation data for the calculations. The physical properties of the pseudocomponents were determined from existing correlations and from matching laboratory steam distillation data. The use of simulated distillation data eliminates the uncertainty and assumptions normally involved in the selection of crude oil pseudocomponents with U.S. Bureau of Mines distillation data, and thus improves the reliability of the proposed computational approach. The proposed approach eliminates the need to conduct experimental steam distillation tests if simulated crude oil distillation data are available. It is easy and fast to calculate the overhead yields ahd densities without use of the equation of state (EOS) and uncertain pseudocomponent critical properties and interaction parameters. The proposed approach will provide useful information for the numerical simulation and design of thermal recovery processes and for the prediction of hydrocarbon recovery from high-temperature volatile oil and condensate reservoirs.